Wait a minute! How many different types of printing are
Printing is as old as civilization itself, going back to impressions on clay tablets in early Mesopotamia before 3000 BC. Using blocks or stamps on cloth or paper dates from ancient Asia and migrated to Europe. Oversimplifying, the history of printing is basically about using available technology to allow an original “by-hand” process to be mechanized, streamlined, and made less expensive. making mass production possible. Printing is about communication. If you want to learn more, check out the Wikipedia articles on the history of printing.
There are many methods of getting an image onto a surface, but for the purposes of this article and probably most average printing projects (on paper), let’s deal with three:
Offset Printing: “lithography” using ink, plates, and a press
Digital Printing: using toner and drums
Inkjet Printing: using inkjet heads
Offset printing is what most people envision when they think of “traditional” printing. It takes an image to be printed, whether physical copy or computer file, and transfers it to a plate which is used on a press. Plates today are made of metal, polyester, or even specially treated paper. Before computers the item to be printed (text or image) would be photographed with a special camera and film. The film would then be used to expose an emulsion on the plate, and the plate processed to contain the image to be printed.
When printing in more than one color, a separate plate has to be made for each color. Again, before computers this was all done by hand, either using masks cut to block or reveal information to be in certain colors, or by the use of filters to separate full color images into the four “process” colors (Cyan, Magenta, Yellow, and Black, or CMYK).
The manual process of plate preparation, color separation, and plate production is as much art as science. The role of the press operator in controlling the lay-down of ink, constantly adjusting the press to achieve the best color and quality is also a combination of craft and science, and the level of human skill plays a vital part in the final product. Nowadays computers have done much to help with the streamlining of this process and have expanded the possibilities of what can even be done on a press. Even with the advent of modern technology — and its availability to more and more of the general public — it takes a team of talented and skilled people to achieve the best results. Printing is still, and always will be, a human endeavor.
Since offset uses actual inks, it can print specially formulated colors, called “spot” colors, developed and standardized by Pantone LLC. There are other companies besides Pantone that have color “libraries,” but the Pantone Matching System (PMS) is by far the most commonly adopted model in America, and worldwide. Think of them like paint colors. Each has a mixing formula using a baseline of primary pigments. There are swatch books full of color chips for selecting colors, and for assuring a color match on the press while the job is running. Spot colors were developed for several reasons: (1) to make printing in fewer than the 4 process colors possible; (2) to achieve colors that are outside the capability of process color; and (3) to allow for unique “signature” colors for a company’s branding style.
So, when should I choose offset?
If you read the previous information about offset, you now know that the bulk of the effort (and, therefore, the cost) of an offset job is in setting up the press to run the job. So you don’t want to go through all that and only make 50 copies of something. Use offset for:
• longer runs, higher quantities (500 minimum of any 1 original is a rule of thumb)
• if you need special color matches using the PMS spot color system
• if you want more choice of papers and printing subtrates
• if you want the traditional look and feel of ink on paper
• if you need a capability that other methods cannot provide
Digital printing is where technology has made possible things that could not be done before. Digital printing here refers to a solid toner-based process, as opposed to offset’s liquid ink method. (There are also digital offset presses, which are setup and operated using sophisticated digital controls, but that is still an offset plate and ink process.) In digital printing, a computer file is interpreted by a device called a RIP (Raster Image Processor), which communicates with a sophisticated digital printer. A solid powder called “toner” in the four process colors (CMYK) is applied to a “drum” and adheres via static electricity. (Amazing, right?!) The colors are then transferred to the paper, which goes through a heated fusing process (some also use an oil) to bond the toner to the paper, and you have your final product.
While every piece of production equipment requires setup for a job to run properly, digital setup is normally much less involved than offset, and is therefore less expensive initially, and makes printing in smaller quantities more affordable. This short run capability has led to the world of “print on demand,” which means you can just print it as you need it, rather than having to store it and risk having timely material go out of date. Editing and revising for timeliness is much easier.
Variable Data Printing (VDP) and Personalized Communication
Digital has also opened the door to creating communication pieces that can be personalized for an individual, a powerful and proven effective marketing tool. Because separate physical plates are not involved, software now exists for computers and RIPs to make 1-on-1 marketing a reality.
Off-the-Glass and Digital Archiving (Scanning)
While relying mostly on electronic file output, most digital printing equipment has a built in scanner, yielding two great advantages. If you have only a hard copy of your item all is not lost. The digital printer is also a photocopier and can produce your job “off-the-glass” by photocopying the original. However, it’s the scanning capability where digital shines brightly. Scanning can be done usually in bulk, depending on the condition of the originals. Scans can be saved as searchable PDF files, effectively creating a digital archival storage system, greatly reducing the paperwork and amount of space needed for record-keeping. Scanned documents can also be processed with OCR (optical character recognition) software that will yield an editable document. Your original can be reconstructed and saved in an editable format.
The Technology Paradox
Since computers have now taken over our lives (kidding, we hope!), we sometimes fall into the trap of believing everything that comes out of them, or that we put into them. With the development of computers came the growth of “desktop publishing.” Now printers receive files from myriad sources, human and electronic. A file may be Microsoft Word, Excel, PowerPoint, or Publisher; Adobe Illustrator, Photoshop, or InDesign; QuarkXPress, CorelDraw, or any one of a number of smaller players in the graphics game; or a PDF file created from any one of these software packages. Each one defines color in a different way — far beyond the scope of this little article to go into the detail of all that. All of these applications are available to the general public (and to businesses), so there’s also the variable of the skill level of the file creator — is she a professional, or is he a novice?
Let’s just say that controlling color in digital printing is a big big challenge, and is sometimes subject to some inconsistency. And the printer itself can be inconsistent from time to time. There is color management software, calibration, and quality checking, but remember that these machines use static electricity in the printing process, which can also be affected by something as humidity and barometric pressure. So it’s possible that a dry sunny day may produce a different result than cloudy with a chance of rain. Your printing will still look very good, just maybe not exactly the same on a repeat job. A factor to consider.
Also, digital may not be a candidate if you’re going to be reprinting on the finished piece using an office printer or laser printer. Examples include letterhead and envelopes. Because digital uses a toner and heat process, feeding back through another printer using a heat process often causes the original printing to flake off from being cooked a second time. Stick to offset for things like that.
Use digital for:
• shorter runs of smaller quantities
• variable data and personalized printing
• jobs where color matching is not critical
• fast turnaround, print-on-demand
• full color printing where offset is too costly or not appropriate
Professional inkjet printing is mostly used for one-off or short runs of large format items, such as signs, banners, posters, fine art applications, and so on. Think of your inkjet printer if you have one — think about how inexpensive the printer itself is, but what it costs to refill it with ink. It’s often less expensive to just buy another printer. Well, professional inkjet printers are still costly, but the ink is also expensive. But the number of inks used (sometimes 6 or more) and the fine resolution of the spray of ink from the heads often allows the inkjet method to produce a wider and more vibrant range of colors than other methods, making it a good choice for situations where brilliant eye-catching colors and graphics are important. Inkjets can also handle a variety of substrates — matte, gloss, textured, canvasses and fabrics, and synthetic materials such as vinyl and polyester. If the printer uses UV “solvent” based inks, printing can be done for outdoor applications without risk of running or fading. Use inkjet for:
• art reproduction, photo enlargements over 18 inches
• signs, banners, trade show materials, retractable banners (stands)
• any large format items over 18 inches
• unique, one-off or small quantity items
• posters, décor items, large pieces for mounting
• window clings, vehicle wraps, indoor and outdoor advertising
WHEW! THAT’S A LOT!
This only scratches the surface of the ins and outs of the various printing methods available to you today! At AlphaGraphics Duluth, we pride ourselves on our customer service, which means finding the right and best methods for your jobs to look their best, while still trying to help you save a dollar along the way.
Visit our website (us726.alphagraphics.com), send us an email (firstname.lastname@example.org), or give us a call (770-925-2530). We’re more than happy to discuss your project with you!